Manufacture of glue and gelatin



Aug. 1, 1950 J. E. HILL ETAL MANUFACTURE oF GLUE AND GELATINE Fil'ed Feb. 20, 1947 JOI/0 MATER/4L OUTLET Patented Aug. 1, 1950 2,517,487 MANUFACTURE OF GLUE AND GELATIN J ohn E. Hill and Norman C. Hill, Akron, Ohio; said John E. Hill assignor to said'Norman C. Hill Application February 20, 19457, Serial No. 729,814

. l This invention relates to the manufacture of glue and gelatine. More particularly, it is concerned with improvements in the procedure used for cooking glue or gelatine out of collagen containing material, such as bones and hides.

Glue and gelatine are chemically similar in composition and, actually, glue can be considered to be gelatine of an impure form. Consequently, the same general procedural steps and the same general apparatus are used for the production of either of these two products.

The source of glue or gelatine is collagen containing materials such as bones, hides or ossein, from which the glue or gelatine is obtained by a procedure which is sometimes referred to as the cooking operation andat other times is referred toas an extraction process, a hydrolysis process or other similar terms used by the trade. For the sake of simplicity, this particular general operation will be referred to herein in as a cooking step.

The cooking of collagen containing materials is generally conducted in a pressure vessel or tank designed to hold the collagen containing material and permit this material to be contacted With hot, aqueous, cooking liquors. The operation is begun by charging the pressure vessel with collagen containing material which has been suciently subdivided to permit the material to be efficiently contained within the vessel without unduly preventing the cooking liquors from percolating therethrough. The particles of collagen containing material are then subjected to one or more' cold Water Washes which serve to remove foreign substances such as blood and other coldr Water soluble materials fromlthe collagen containing particles. This Washing operation may be dispensed with if glues of only inferior quality are required.

After the particles have been sumciently washed, they are drained free of the Wash water and the pressure vessel is filled to an appropriate level with hotwater; The collagen containing material inlet ports of the pressure vessel are thenclosed and live steam is introduced directly into the tank, or steam is circulated through a heating jacket, as required in order to maintain the cooking liquor temperature at the `desired level throughout the entire cooking process. At the completion of the cooking step, the grease layer which forms upon the surface of the cooking liquoris drained off afterwhich the cooking liquor, which now comprises an aqueous solution of glue or gelatine, is removed from the cooking vessel and conveyed to the subsequent sections of the manufacturing plant.

11 Claims. (Cl. 260-118) The collagen containing material in the cooking vessel is subjected to repeated cooking steps which are continued for as many times as is nece'ssary` to -convert as much of the collagen con` tained `therein to glue or gelatine as is economically feasible. In common practice, prior to the presentinvention, each cooking step generally required up to fteen minutes in the case of hides, `and up to one hour in the case of bones. The total time consumed for the entire group of cooking steps in order to completely convert the collagen from a particular batch of bones or hides is generally in the neighborhood of up to twelve hours where the cook charge is hides or ossein, and up to fourteeen hours or more where the cook charge is animal bones.

It is awell-knovvn fact that, if an aqueous solution of gelatine or glue is maintained at a substantially elevated temperature, such as the temperatures prevailing during the cooking operations described above, the glue or gelatine is degraded and loses a portion of its desired property referred to `as body or gel strength. Consequently, it is necessary, in order to produce a satisfactory glue or gelatine product, that the cooking liquors shall not remain in contact with the collagen containing material during the cooking step for more than a short period of time. This reduction in the amount of time which can be given to any individual cooking step results in the production of glue and gelatine solutions `in each step of relatively 10W concentration since the cooking steps may not be carried on suincientlylong to permit the solution concentration to` greatly accumulate.` The problem of heat control and ecient Contact of the cooking liquors with the collagen containing material during the cooking operation is further aggravated by the fact that, in order to make ellicient use of the cooking vessel, itis necessary to rather iinelysubdivide the collagen material. Thus, with the bones or hides charged into the pressure Vessel as vsubdivided particles, the cooking liquor eX- hibits a very great tendency to channel down the sides of the pressure vessel. This uneven distribution of cooking liquor prevents the center of the mass of particles from being heated to the required degree and the particles there from being contacted with the cooking liquor to the required extent. l

i It has longv been recognized in the trade that, ifa more efficient Way of circulating the cooking liquors about the collagen containing material particles and of insuring that the middle sections of the solid mass is heated as rapidly as the surroundingportions could be found, then solutions of higher concentration of glue or gelatine could be produced in shorter periods of time with the nal result that glue or gelatine products of much higher gel strength would be obtained. This would result not only because it would not be necessary to maintain the cooking liquor at elevated temperatures for undesirable lengths of time during the cooking step; but also because less heat Iand shorter periods of time would be required for concentrating the glue or gelatine solutions obtained as a result of the cooking operations.

A principal object of this invention is the provision of new methods for usei-n themanufacture of glue and gelatine. Further objects include:

1. The provision of a new method for circulating cooking liquor throughouty the collagen containing material whereby the entire `masslof the material is more uniformly heated and contacted withgtheA cooking liquor;A

2. Thrlv .provision of; a collagen material. cookingoprecess4 which :permits higher concentrations oglue'aor gelatine solutions. tov be .obtained in shorterfiperiods of.v time than the cooking proce.- dures. employed. Aheretofore.

3;.The :provisionofa glue. or gelatine productionY process which ymakes .possible substantial savings in heat .and power.,v required for carrying outthe cooking step.;

4.! The .provision of. amethod for use in the eicientcirculation of cooking liquors in glue and gelatinemanufacture involving mechanical movin'g'parts, such :a.s..purnps,y thusgiving great, clean.

linessA of .operation- Still further .objects and :the yentire scope of,

applicability of `.this invention will'become. apparentl fromfthe. detailed description given .hereinaftenbut it should be realized thatthespecic scription, are .merely by, .way of illustration and thatthe-.invention is basically broader than these.

speciic embodiments in..view:,1of .the..fact-.-that various-modifications and alterations withinthe spiritv `of the invention l will l,be Japparent. to..those.

skilled-in the art.

The newlprocedures provided by thiszinvention caribe --moreeasily comprehendedby reference tothe-attached drawing in which: x

Figure 1 isa .'verticaleection throughonespecic-formcof cooking vessel utilizing. the features of 'thisf invention;

Figui-e l2 yisha transverse sectional view .along theline 24diet-Figure 1 with the `collagen/confl tain-ing material particles containedin -thevessel illustrated in Figure l removed.

Referring in detail to thek drawing.: the cooking apparatus consists of a cylindrically-shaped pres. sure -vessel 2 `providedwith a dome-shaped'top. 4 and a dished bottom 6, both of which are welded to the/sides of `the vessel: 2.

The vessel is provided with inlets and outlets which consist of a solidmaterial inlet 8 andra liquid inlet lllfboth fastened inthe topof the Vessel,` such asby welding,fa plurality of side entering grease drains I2 and I4, anda solid ma'- terial outlet I6 and liquid material outlet I 8, both located onthe bottom of the vessel.

The inlet 8 and the outlet I6 are oi the common manhole type employed with pressure vessels andare provided with covers and 22, respectively. The covers 20 and 22 have associated therewith clamping means 24 and 26 which serve to'hold the covers 2U and 22 in vapor-tight association with the pressure vessel.

The liquid outlet I8 is preferably situated in the exact center of the dished bottom 6 to insure that all of the glue or gelatine solution produced in a cooking operation will be removed at the completion of each cooking step, so as to prevent putrecation from taking place within the cooking vessel between batches. The outlet I8 is connected through a valve 28 to a glue or gelatine solutionstorage tank, not shown.

In the lower portionof `the pressure Vessel, there is located a frustro-conical partition 3U having perforations 3| therein. The apex end of the partition communicates with the solid material outlet I6, while the base end joins the inner surface ofthe. walls 2 a substantial distaneeup the side of the vessel from the bottom 6. This partition 38, which may also be referred to as a perforated false-bottom, serves to hold the .particles of collagen containing material suspended above the bottom 6 of the vessel and permitycookingfliquorto. circulate freely` along the bottom:portion of .the vessel. The fpartition. furtlierfinsures `the discharge of all of the cooked soldwparticlesfrom the vessel 2 thrOughthe-Outlet I6.

Allfof the .portions of the apparatusfdescribed abovepare. standard featuresaof glue or `gelatinecookingvessels.. The .novel features of this invention.center mainly=around `the open end tube 32- and .elements associated therewith... Thisitube is supported withinrthe:.pressurewesselfZ :inra vertical:position.,.preferablyrnear the .center of the vessel, .but.not; directly;.over.the .outlet:.l8,k

by meanspof. the. supports or. braces.. 134. and 136.. The bracesl should baplaced-within the vessel.

2 so-.thatrmaterialcharged into the vesselthrough thesinlet-f `willtnot fall .upon :any 10i zthe, braces and., rbecomeilodged; there. ltomputrefy. Thek tube 32is of Lsuch .length that, when .sopositioned with-,- in the vessel, the lower open endioffth'e: tube 38 comes within a short distance of thevessel bottomigvrhile the. open itop end-o. the tube: comes within a short'distance of the topA The frustrecon-icalxpartition .intercepts thettube 32 at a point Vlita short distance above the lower .open end 38.0f the tube.

There extendszinto thebottomopen end 38 of the tube132 a .jet tube 42-which lis-of appreciably smaller diameter than the tube 32r and which has its' Ajet endsl extending ashort distance into the .bottom interior of the' tube 32. The opposite endy 46=ofzthe tubezorpipe 42 passesthrough the bottomr ofzthe vessel and is'held in vapor-.tight connectionV therewith byA means `oi the ange or" bushinglit.'A The end of. the jet tube 46,V outside ofthevessel- 2, isconnectedby means of the elbow-5 iand .pipe v52.toa source otuid, e. g., afsource of steam, .connected to:pipe;54 through valve 56 and a source of air pressure connected through;the .pipe 58` and the valve 60.'

At the; top;` of. then verticaily .,positioned; tube 32,l 'there 'is positioned, Asuch as. lby rivetingAv or welding tothe top 4, an arcuate partition or umbre11a.'62. The .purposez of this: umbrella 62. isxto distribute liquid. which .issues :from: the end ofV the ltubeni32: ,evenl-ynover the*y entire surface'of the: collagen-containing particles 64V contained withinfthe pressure vessel.

A smallivapor escape. means 65. vinLthetOp 4 ofzthe vessel may be provided.. Thism'eansz 65 may :be a pressure relief. valve@ small .stopor pet.cock;;,or any other device of this'type which is capable-of allowing :a small, controlled amount of. vapors Yin the vessel to ,escapa With thespecio features. of. one preferred embodiment of the apparatus. `of lthis` invention de,

ais-17,1187

i l'M scribed and illustrated, the mode of operationof thepresent invention may now be described.

The collagen material which has been' subdivided to form particles of proper size for efficient charging of the pressure vesselare loaded into the vessel 2 through the inlet 8. Cold water is then introduced into the vessel through the inlet ID and when the water level risesto a desired height, such `as three-quarters of the Way up the vessel, the water is caused to` circulate throughout the entire mass ofthe collagen containing particles by forcing a stream of air at relatively high velocity-for example at twenty pounds per square inch or greaterinto` the base of the tube 32 through the jet tube 42. Thus, air streams into the base of the tube 32 in which there is contained a minor portion ofthe wash water, and the combined effect of the cocurrent force of the air stream and the resultant decrease in density of the wash water portion contained in the tube 32 due to the presence of bubbles of air therein, causes `the portion of wash water contained in the tube to pass up the tube 32 and to be forcibly ejected from the top open end 40 thereof. This ejected portion of water strikes the umbrella 62 and as a result, is evenly distributed over the entire top surface of the collagen particles 64. Continued ejection of air through the jet tube 42 causes further portions of the wash water to enter at the base ofthe tube 32, then to rise up the tube, and to be forcibly ejected at the top. As a result, ei'lcient circulation of the wash water throughout the entire mass of the collagen containing particles 64 takes place in a fashion which is illustrated by the arrows on Figure 1. This method of producing a liquid circulation is sometimes referred to as the air-lift or fluid-lift principle.

After the wash water has been circulated about the collagen containing particles for a sufficient length of time, the valve 28 is opened and the wash water permitted to drain from the` vessel through the liquid outlet I8.` This washing operation is conducted with further portions of fresh cold water` until substantially all of the foreign material, such as blood and other substances contained upon the collagen containing particles is removed. i

After the washingoperation is completed, the inlet 8 is closed by means of the cover 20 and sufficient hot water is introduced through the liquid inlet l0 to lill the vessel 2 to very near the top of the level of collagen containing particles 64. Steam is now ejected through the jet tube 42 into the tube 38 by opening the `valve 56. In much the same fashion in whichl the cold wash water is forced to circulate `throughout the vessel by the ejection of air, the steam which is ejected from the jet end 4400i the tube `42 into the tube 32 causes succeeding portions of water to rise up the tube 32 and to be forcibly ejected from the open end 40 at the same time the latent heat contained in the steam serves to heat the water to provide` the heat necessary to `maintain the circulating glue or gelative 4solution at the temperature required for the eicient hydrolysis and extraction of glue and `gelatine from the collagen in the particles 84.

The mass of particles `64 contained in the cooking vessel 2 israpidly and uniformly heated to the cooking temperature because firstly, the even `distribution of the cooking liquorwupon .the en- -tire surface of the particles 64 causes the liquor to be circulated uniformly throughout the` mass iof .the particles,secondlyithe tube 32 which becomes heated by the steam passing internally up through the tube and transfers its heatto the cnl tral portion of the collagen containing material which has been charged into the vessel. Inother words, the problem of effectively heating the cen-5" ter portion of the collagen containing material during the cooking operation is solved by the present invention not only because the tube 32 andthe fluid-lift principle associated provide for unus` ually good circulation of the cooking liquor, but also because the centrally positioned tube aids in transference of heat to the central portions of the mass being treated. Moreover, this tube serves to prevent the collagen containing particles from becoming unduly packed at the center "of the mass and serves to keep the center of the mass open so that proper circulation of the liquor throughout the particles may take place.

By continuously venting a portion of the vapors in the vessel through the escape means 65, fresh supplies of steam may enter the vessel even when the internal pressure approaches that of the steam pressure. Furthermore, continued venting through valve 65 aids to remove oxygen from the vessel with the result that the glue or gelatine is less degraded at cooking temperatures and a better product is obtained.

After the hot cooking liquor has been circulated by means of the ejected steam for a sufficient length of time to produce a glue or gelatine solution of adequate concentration, the hot solu-` tion is immediately Withdrawn from the vessel through the outlet I8 by opening the valve 28.

Thereafter, the valve 28 is closed and a fresh quantity of hot water is introduced into the vessel through the liquid inlet lll. Ilihe ejection of steam and circulation of cooking liquor is repeated after which the resulting glue or gelatine solution iswithdrawn in the same fashion as indicated above for the first cooking step. These cooking steps are repeated until a solution of sufficient concentration of glue or gelatine can no longer be obtained from the exhausted particles charged into the vessel as tankage. At this point, the outlet I6 is opened and the exhausted particles are removed from the vessel. The entire operation is then repeated by recharg "ing thevessel with new collagen containing material, going through the washing steps and iinally the cooking steps.

Several units may be operated together `in combination of three or four, introducing hot water into the lowest collagen containing batch` and withdrawing the concentrated solution from the pressure vessel containing the stock with the highest collagen content. The unit may, therefore, be operated, strictly batch, semicontinuou`s, or as continuous group units withdrawing the spent vessel from the operating group for` removal of the tankage (remaining residue) and `continuing to extract collagen from the charges in the other units.

Substantially any solid materials which contain collagen in suiiicient quantity to make possible the commercial production of hydrophilic animal .protein material, i. e., glue or gelatine therefrom `may be treated in accordance with this invention. Thus, green bone, country bone, ossein, horn pith,

sinews, hide stock, or the like, may all be eifecn tively cooked. However, the conditions and times required for the cooking of different materials will, of course, vary with the material whicliis treated. Thus, temperatures in the` neighborhood of,` F. or lower are preferred forrtlie cooking of hides, whereas temperaturesinthe treated. However, the required time for a given step -is materially less in the cases where the present invention is employed than for operations Where previousrmethods of cooking and liquor circulation, e. g., ,circulation of cooking liquors by; means of pumps or by the simple injection offraw'steam into the base of the pressure vessel.- Thus,iwhereas up to iifteen minutes or more for each cookingv step are generally required for the treatment of hides .and one hour or more are generally required "for each step in the cooking or animal bones-a Asingle cooking step may be accomplished withour process in a periodof a few minutes in the case of hides, and in substantiallyy .less .than one hour, e. g., one-quarter hour to-one'half hour,in the case of animal bones. Furthermore, sincethe collagen containing material is raised to cooking temperature much more rapidly `bythe present process than with the procedures used heretofore, it is possible to produce glue or gelatinesolutions of higher concentration without appreciable loss of gel strength. Thus, while it is generally not possible to obtain glue orgelatine solution of concentration greater than 11% with procedures employed heretofore, it is possible to produce solutions of glue or gelatine of comparable gel strength from the same basic materials in concentration between 14 and 18%. Hence, this invention provides saving in the amount of time and the total heat required to evaporate and concentrate the resulting glue or that the principles and apparatus involved herein are broader than the structures specifically described above, and rather than attempt to list the `numerous modifications with which we have experimented and, instead restrict the descrip- ,f

tion to those which we have found to be best in practice, we define these principles and apparatus in the appended claims.

The term gelatine material as used in the ,accompanying claims is intended to cover both glue and gelatine and similar products generally portion is prevented from intermingling with the remainder of the liquid when said fluid is ejected therein, whereby a solution of gelatine material offhigh gel strength containing substantially no dissolved bloodis obtained.

2. A process for the manufacture ofgelatine material from solid particles of collagen containing material which comprises contacting the collagen containing material with a hot aqueous,

treating .liquid and causing circulation of the liquidthroughout said material by ejecting a strean'ofl fluid at 'relatively high 'velocity vertically'into' la-"niinorportion of rsaid liquid, which minorportion is confinedfalong a verticalpath extending substantially throughout the Vd epthof said' liquid-'out of direct contact with the main portion of said liquid, whereby a'solution ofgel'atiie material'of high gel strength containing subst'ant'ially no dissolved blood is obtained.

. 3.- A process for the manufacture'of 'gelatine' materialI from collagen containing material which comprises treating vparticles of collagen contain`` ing material with a body of hot, aqueous, treat-J ingJiquid and causing circulation of said liquid throughout said particles by ejecting steam vertically intoa small portionof said Yliquid body, which liquid portion is confined along a vertical path whereby -it 'may flowl only vertically and may not intermingle with the main portion 'of saidliquidbody .until it emerges from said conningfpath, whereby a solution of gelatine material of high gelY strength containing substantiall-y-rlo dissolved blood is obtained.

f, 4.-.The process of 4claim 3, wherein said-steam isejected into said minor liquid pcrtionvat'relativelyhigh f velocity.

5. A` processY for the manufacture of gelatine material which comprises washing a quantity of solid'- lparticles of collagen containing material withf-an `aqueous wash liquor, causing circulation of the wash `liquor throughout said-particles by ejecting a stream of air -at relatively high velocity into 4`alminor portion vof the total-wash liquor withsaidminor'portionfffrec to flow only in-a verticalpath out=of contactvwith the remainder ofthe-liquorfuntilsaid liquorportion has-reached an upward level above the level'of the remainder of the liquorl after which said liquor portion may contact said particles i and the remainder v of- "said liquor; permitting'further portions of said' -liquor to' -lreplacethe vfirst-named portions which now through tsaid con-fined vertical path, vcontinuing the circulation of washingv liquoruntil the 'para ticles'o'f collagen-*material are freed of 'substantially all material ywhich maybe-removed therefr'om 'bycold water washing, removing the' wash liquorflfromcontact with the collagen material', contacting the washed collagen particles with an aqueous *cooking liquor, causing said'A cooking liquo'rto be heated'andsimultaneously circulated throughout said-'particles by ejecting a stream' of steam into aminor portion of said cooking liquor -in= themanner aforesaid for saidl air stream `with Saidewashing liquor, continuing said' circulation :of heated cooking-liquor throughout said particles until 'asolutio'n of appreciable solid Vconcentration fr'ee ofA any dissolvedj blood is obtained, 'and then removingi the 'resulting' solution 'from contact with said particles. f Gi''Theprocess of claim 5,"wherein^said-par ticlesfffcollagen containing material are ground animal bones? V 7.' process-of `claim-5,A wherein the resulting solution of gelatine -:material removed from saidfparti'cleslis employed as the cooking liquor for ycdritac't with further collagen containing'material havin'g'"a collagen content higher thantlie first treated .collagerif containing material.

vSLfIhe' processfof'treating collagen containing f-mrenarw produce-gelatine materiarwhichfcom'- prises cooking said material in an aqueous 500k". ing liquor""arid passingA a J'et'of fluid and" a rni'n'or laci'rtionI of said liquor cociirrently upward along a ,co'nfi'nedjpathwithinnthe main portion offsa'id liquor without permitting 'said separate portions of liquor to admix until said minor portion has proceeded to a height above the liquid level of said main portion and collecting a solution of gelatine material of high gel strength containing substantially no dissolved blood.

9. The process of claim 8, wherein said jet of fluid is a jet of steam.

10. The process of claim 1, wherein said jet of fluid comprises a jet of steam which supplies the heat required for the cooking process.

11. The process of claim 3 wherein a small portion of the vapors above the process reactants is continuously removed during said steam ejection.

JOHN E. HILL. NORMAN C. HILL.

10 REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 360,996 Buttner Apr. 12, 1887 400,441 Cooper Apr. 2, 1889 1,063,229 Upton June 3, 1913 1,198,541 Hardesty Sept. 19, 1916 1,404,701 Psterer Jan. 2'4, 1922 1,763,845 Edgerton June 17, 1930 1,943,330 Mitchell Jan. 16, 1934 

5. A PROCESS OF THE MANUFACTURE OF GELATINE MATERIAL WHICH COMPRISES WASHING A QUANTITY OF SOLID PARTICLES OF COLLAGEN CONTAINING MATERIAL WITH AN AQUEOUS WASH LIQUOR, CAUSING CIRCULATION OF THE WASH LIQUOR THROUGHOUT SAID PARTICLES BY EJECTING A STREAM OF AIR AT RELATIVELY HIGH VELOCITY INTO A MINOR PORTION OF THE TOTAL WASH LIQUOR WITH SAID MINOR PORTION FREE TO FLOW ONLY IN A VERTICAL PATH OUT OF CONTACT WITH THE REMAINDER OF THE LIQUOR UNITL SAID LIQUOR PORTION HAS REACHED AN UPWARD LEVEL ABOVE THE LEVEL OF THE REMAINDER OF THE LIQUOR AFTER WHICH SAID LIQUOR PORTION MAY CONTACT SAID PARTICLES AND THE REMAINDER OF SAID LIQUOR, PERMITTING FURTHER PORTIONS OF SAID LIQUOR TO REPLACE THE FIRST-NAMED PORTIONS WHICH FLOW THROUGH SAID CONFINED VERTICAL PATH, CONTINUING THE CIRCULATION OF WASHING LIQUOR UNTIL THE PARTICLES OF COLLAGEN MATERIAL ARE FREED OF SUBSTANTIALLY ALL MATERIAL WHICH MAY BE REMOVED THEREFROM BY COLD WATER WASHING, REMOVING THE WASH LIQUOR FROM CONTACT WITH THE COLLAGEN MATERIAL, CONTACTING THE WASHED COLLAGEN PARTICLES WITH AN AQUEOUS COOKING LIQUOR, CAUSING SAID COOKNG LIQUOR TO BE HEATED AND SIMULTANEOUSLY CIRCULATED THROUGHOUT SAID PARTICLES BY EJECTING A STREAM OF STEAM INTO A MINOR PORTIONOF SAID COOKING LIQUOR IN THE MANNER AFORESAID FOR SAID AIR STREAM WITH SAID WASHING LIQUOR, CONTINUING SAID CIRCULATION OF HEATED COOKING LIQUOR THROUGHOUT SAID PARTICLES UNTIL A SOLUTION OF APPRECIABLE SOLID CONCENTRATION FREE OF ANY DISSOLVED BLOOD IS OBTAINED, AND THEN REMOVING THE RESULTING SOLUTION FROM CONTACT WITH SAID PARTICLES. 